The present invention generally relates to an image information communication apparatus, and more particularly to a facsimile machine equipped with an image memory for storing image information.
Conventionally, facsimile machines have various functions, such as a memory transmission function, a memory receive function and a confidential receive function. In the memory transmission function, image information on a transmission document is stored in an image memory immediately and is then sent to a destination facsimile machine. In the memory receive function, an image memory is supplied with image information which is received in a state where it is impossible to record an image on a photosensitive drum. In the confidential receive function, received image information is stored in an image memory and is then output therefrom when an identification code is input. As described above, image memories built in facsimile machines are provided for realizing various functions.
Conventionally, such an image memory is formed of a volatile random access memory (RAM). Thus, when the power supply is turned OFF due to the occurrence of a power failure, image information stored in the image memory is erased. In order to overcome the above-mentioned problem, management information related to image information stored in the image memory is stored in a non-volatile memory, such as a battery-backup RAM. For example, the battery-backup RAM is supplied with the image information file number, the type of process, the destination terminal, the number of pages of a document to be transmitted, the storage time and so on. If the power supply happens to be turned OFF and is then restored to the ON state, a power-OFF report is printed out, which reports the above-mentioned management information together with the time when the power supply was turned OFF.
The operator acknowledges image information which has been erased from the power-OFF report. Then, the operator retries a transmission operation on the erased image information or requests a communication party to send the related image information again.
A conventional facsimile communication uses a special signal related to a transmission control procedure, such as a CSI signal. Such a special signal is directed to notifying the destination facsimile machine of transmitter identification information, such as the telephone number of the transmitter. Some conventional facsimile machines do not have the function of implementing such a conventional facsimile communication procedure. When a facsimile machine having the aforementioned various functions receives image information from a facsimile machine which does not have the above-mentioned facsimile communication procedure, the destination facsimile machine encounters the problems described below. If the power supply to the destination facsimile machine is turned OFF and is then restored to ON, the destination facsimile machine outputs the power-OFF report. It will be noted that this power-OFF report does not contain any information directed to identifying source facsimile machines, such as the telephone number. For this reason, the operator cannot identify source facsimile machines and cannot request source facsimile machines to send the related image information again.
If the source facsimile machine has the function of sending identification information, the operator on the destination side can identify the source facsimile machine. However, the operator cannot precisely specify image information which is requested to be retransmitted. For example, the operator cannot precisely specify a document which was transmitted from the source facsimile machine at a certain time. In a case where a plurality of documents each having an identical number of pages have been received from the same source facsimile machine, it is very difficult for the operator on the side of the source facsimile machine to determine which one of the documents should be retransmitted in response to a retransmission request from the destination facsimile machine.
On the other hand, generally, documents which are transmitted in the confidential transmission mode should be kept rigidly secret. Thus, generally, the operator on the transmission side communicates with the operator on the receive side person to person and sends image information in secrecy. From this point of view, it is not desirable that a third person know, based on the power-OFF report, the fact that confidential image information has been transmitted.
As has been described above, according to the conventional facsimile machines, it is very difficult to identify a document which has been deleted from the image memory and to keep rigidly confidential image information secret.